blender game controling
is a great video for your problem. it does involve some python but that's mostly taken care of in the description.

http://www.youtube.com/watch?v=-IeNnw6zzvQ

if your character want to walk though walls and obstacles just to get to the pointer, you'll have to set up a more complex NavMesh.
this is basically a mesh that covers all the area that the characters have access to.